Distal protection devices having controllable wire motion

ABSTRACT

A distal protection device for use in a body lumen. The device includes a functional element which may be a filter or an occlusive element. The device includes means for controlling the movement and placement of the functional element along a guidewire. Motion of the guidewire can be independent of the motion of the functional element.

CROSS-REFERENCE TO RELATED APPLICATION

This Application is a divisional of application Ser. No. 10/915,171,filed Aug. 10, 2004, which is a divisional of application Ser. No.10/093,572, filed Mar. 8, 2002, now U.S. Pat. No. 6,773,448 B2, issuedAug. 10, 2004, the contents of each of which are hereby incorporatedherein by reference.

FIELD OF THE INVENTION

This invention relates to devices used in a blood vessel or other lumenin a patient's body. In particular, this invention relates to distalprotection devices having a guidewire which can be controlledindependently of a functional element such as a filter which is carriedby the guidewire.

BACKGROUND OF THE INVENTION

During vascular surgery or endovascular treatment of vessels includingatherectomy, balloon angioplasty, and/or stent deployment, debris suchas plaque and blood clots can move from the treatment site through avein or artery, thus compromising the flow of blood at a location distalfrom the treatment site. Various distal protection systems have beendeveloped to prevent such debris from embolizing in the vessel. Suchdistal protection devices include filters and occlusive devices, (e.g.,balloons) placed distally of the treatment site.

It is desirable to place a distal protection device at a chosen locationin order to achieve good sealing between the device and the wall of thevessel. Frequently it is necessary to match the protection devicediameter with the vessel diameter, and vessels are known to taper or tohave diameters that vary due to disease. It is also desirable to placethe protection device in a relatively disease free portion of the vesselso as to minimize liberation of emboli from the wall of the vessel dueto interaction with the protection device. Further, it is desirable thatthe device remains at the desired location during the procedure.Excessive motion of the wire or elongate guide member used to deliverthe device can advance a protection device distally, beyond branchvessels, which thereby become unprotected from emboli.

Distal protection devices typically are mounted on a wire or tube thatfunctions as a guidewire. As used herein the term guidewire means eithera traditional guidewire or other elongate member or hollow tube that isused in delivering the distal protection device. The protection devicecan be either a filter or an occlusive device such as a balloon. Thedistal protection devices are either fixedly attached to the guidewireor attached so as to permit a limited amount of motion between thedevice and the guidewire. Frequently, the same guidewire used to carrythe device is also used to guide various catheters to and from thetreatment site. For example, during the procedure, catheters may beexchanged over this guidewire. When catheters are exchanged inadvertentwire movement can cause the protection device to move within the vessel.Excessive wire motion can also retract a protection device proximally,where it can potentially become entangled in a stent or even beinadvertently removed from the vessel being protected. In some vessels,when guide catheters are repositioned, the protection device also tendsto move within the vessel. This is undesirable because captured embolican be released and/or new emboli can be formed distal to the protectiondevice, blood vessels can be damaged, and/or the device can entanglewith an implant such as a stent. Therefore, it is clear that too muchmovement of the device within the vessel could have catastrophicresults.

Some work already has been done to provide for limiting the movement ofa distal protection device or distal filter with respect to a guidewire.For example, a guidewire having a distal stop is described in WO01/35857 (Tsugita et al.). The filter slides on the guidewire but cannotslide off the wire due to the distal stop. Another device which includesa slideable vascular filter having both distal and proximal slidingelements that move independently of each other over a mandrel isdescribed in WO 01/21100 (Kusleika et al.) and is illustrated in FIG.37. The device includes filter F, distal and proximal sliding elements(D and P) at either end of the filter, and stop S, all disposed aboutmandrel M. Body B of the filter F assumes a generally tubular shape andis made of a resilient material. The proximal length of the filter bodyhas opening O therein. This opening permits body fluid with particulatetherein to enter the enclosure formed by body B of the filter. Themandrel is sufficiently flexible so that the device can be deployed in acurving body passageway. The distal-most length of the mandrel is shownhaving a flexible helically wound coil T thereover. This coil enhancesthe flexibility of the distal tip. The stop is at a fixed position onthe mandrel and thus limits the movement of the sliding elements D andP. The filter is thus allowed to move along the mandrel or guidewireonly the distance to the stop. While this system meets many of the needsin the art, it limits the range of motion of the filtration device onthe guidewire, and the precision with which it can be placed is limited.

Another known limitation of distal protection devices relates to wirebias. It is well known that a guidewire will conform to the outside of acurved vessel on advancement of the wire in a distal direction and willconform to the interior of a curved vessel during retraction of thewire. Most distal protection devices are attached to wires, and whenthey are deployed in vessel curvature the wire bias will alternatelymove the device between the inside and the outside of the vessel curve.For filters this can defeat the protection effect by compressing thefilter opening. For occlusion devices the wire bias effect can causeexcessive motion of the occlusion device with potential liberation ofembolic debris from the vicinity of the occlusive element.

Some work already has been done to provide for limiting the radialmovement of a guidewire relative to a distal protection device. Forexample, a protection device having a proximal loop is described in EP1,181,900 A2, (U.S. Ser. No. 09/628,212, Oslund et al.). A loop isprovided proximal to the filter to immobilize the wire against thevessel wall regardless of wire bias. While this system meets many of theneeds in the art, it adds bulk to the device and thereby limits crossingprofile.

It would be desirable to have a distal protection system that can beprecisely placed at a location within the vasculature and that canaccommodate a wide range of axial and radial wire motion withoutdisturbing the device's position.

SUMMARY OF THE INVENTION

This invention is a distal protection device for use in a body lumen.The device includes a guidewire system which may include separateindividual guidewire or elongate members. A functional element, such asa filter or occlusive device including a balloon is mounted on theguidewire system. The device is able to filter or occlude debris andblood clots in a body lumen and/or prevent them from moving distally andcausing emboli. The various embodiments of the invention disclosedherein allow the user to accurately place the filter in the vessel andpermit substantial guidewire movement during the filter use withoutdislodging the filter. Motion of the guidewire can be independent of themotion of the distal protection device and the contact force between theguidewire and the protection device can be cushioned in the device ofthis invention. In addition, in some of the embodiments disclosed hereinthe user of the device is able to enable or disable the relative motionfeature between the guidewire and the protection device and/or to obtaintactile feedback to indicate the limit of the range of guidewiremovement when the relative motion feature is enabled.

In a first embodiment, this invention is a distal protection device foruse in a body lumen comprising first and second elongate members havingdistal and proximal ends, a functional element carried by the secondelongate member, the functional element being expandable from a deliveryconfiguration to an expanded deployed configuration when the functionalelement is deployed in the body lumen; and means for moveably connectingthe first and second elongate members over a range of motion from afirst relative position to a second relative position such that when thefunctional element is deployed in the lumen the first elongate membermay be moved without resulting in corresponding movement of thefunctional element, the distal end of the second elongate member beingdistal to the distal end of the first elongate member over the entirerange of motion.

The connecting means may comprise a flexible tether. The connectingmeans may comprise a distal portion of the first elongate member havinga lumen which is configured to slideably receive a proximal portion ofthe second elongate member, the second elongate member having anenlarged proximal end, the lumen of the distal portion having aconstricted portion defining an opening which is smaller than theenlarged proximal end of the second elongate member such that the secondelongate member is slideably retained in the lumen of the distalportion. The connection means may comprise a telescoping connectorbetween the first and second elongate members. The connecting means maycomprise a sleeve having at least one lumen sized to slideablyaccommodate the first and second elongate members, the distal end of thefirst elongate member having a stop positioned distal to the at leastone lumen and sized to prevent the distal end of the first elongatemember from being withdrawn from the at least one lumen, the secondelongate member having a stop positioned proximal to the at least onelumen and sized to prevent the proximal end of the second elongatemember from being withdrawn from the at least one lumen. The functionalelement may comprise a filter, and the filter may have a body defining aproximally facing opening when in the expanded deployed configuration.The functional element may comprise an inflatable balloon or a bodydefining an interior cavity. A sleeve may be contained within theinterior cavity. The connecting means also may comprise a first eyeletat the distal end of the first elongate member and a second eyelet atthe proximal end of the second elongate member, the first eyelet forminga first loop which encircles the second elongate member and the secondeyelet forming a second loop which encircles the first elongate member.

The functional element may include a proximal end connected to thesecond elongate member and a distal end connected to a distal sliderwhich is slideable over the second elongate member, and further mayinclude a loop at the distal end of the first elongate member whichencircles the second elongate member between the proximal end of thefunctional element and the distal slider. The loop may be containedwithin the interior cavity. The connecting means may comprise the firstelongate member having a tubular body having a lumen with an interiordiameter and the second elongate member having a first region with anexterior diameter less than the interior diameter of the lumen of thetubular body, the first region being slideably received in the lumen ofthe tubular body. The second elongate member may have enlarged portionsadjacent proximal and distal ends of the first region, which have anexterior diameter larger than the interior diameter of the lumen of thetubular body. At the first relative position, a first surface of thefirst elongate member can abut against a first surface of the secondelongate member. This may further include means for gradually increasingresistance to movement between the first elongate member and the secondelongate member as the first surface of the first elongate member ismoved toward the first surface of the second elongate member.

The device may further comprise means for moveably connecting the filterand the first elongate member over a range of motion from a firstposition when the connecting means is in a relaxed state to a secondposition when the connecting means is in an expanded state such thatresistance to movement between the filter and the first elongate memberincreases over the range of motion as the second position is approached.There also may be a means for locking the first elongate member to thesecond elongate member, the locking means having a locked position wherethe relative positions of the first and second elongate members arelocked and an unlocked position where the first elongate member can bemoved over the range of motion from the first relative position to thesecond relative position without resulting in movement of the secondelongate member.

In a second embodiment, this invention is a distal protection device foruse in a body lumen comprising a first elongate member having distal andproximal ends, a distal portion of the first elongate member having alumen; a second elongate member having a distal end and an enlargedproximal end, the lumen of the distal portion of the first elongatemember being sized to slideably receive a proximal portion of the secondelongate member and having a constricted portion defining an openingwhich is smaller than the enlarged proximal end of the second elongatemember such that the second elongate member is slideably retained in thelumen of the first elongate member; and a functional element carried bythe second elongate element, the functional element being expandablefrom a delivery configuration to an expanded deployed configuration whenthe functional element is deployed in the body lumen.

In a third embodiment, this invention is a distal protection device foruse in a body lumen comprising a first elongate member having distal andproximal ends; a second elongate member having distal and proximal ends;a functional element carried by the second elongate element, thefunctional element being expandable from a delivery configuration to anexpanded deployed configuration when the functional element is deployedin the body lumen; and a sleeve having at least one lumen sized toslideably accommodate the first and second elongate members, the distalend of the first elongate member having a stop positioned distal to theat least one lumen and sized to prevent the distal end of the firstelongate member from being withdrawn proximally from the at least onelumen, the second elongate member having a stop positioned proximal tothe at least one lumen and sized to prevent the proximal end of thesecond elongate member from being withdrawn distally from the at leastone lumen.

In a fourth embodiment, this invention is a distal protection device foruse in a body lumen comprising a first elongate member having distal andproximal ends; a second elongate member having distal and proximal ends;a functional element carried by the second elongate element, thefunctional element being expandable from a delivery configuration to anexpanded deployed configuration when the functional element is deployedin the body lumen; and a first eyelet at the distal end of the firstelongate member and a second eyelet at the proximal end of the secondelongate member, the first eyelet forming a first loop which encirclesthe second elongate member and the second eyelet forming a second loopwhich encircles the first elongate member.

In a fifth embodiment, this invention is a distal protection device foruse in a body lumen comprising a first elongate member having distal andproximal ends; a second elongate member having distal and proximal ends;a functional element carried by the second elongate element, thefunctional element being expandable from a delivery configuration to anexpanded deployed configuration when the functional element is deployedin the body lumen, the functional element having a proximal end which isconnected to the second elongate member and a distal end connected to adistal slider which is slideable over the second elongate member; and aloop positioned at the distal end of the first elongate member whichencircles the second elongate member between the proximal end of thefunctional element and the distal slider.

In a sixth embodiment, this invention is a distal protection device foruse in a body lumen comprising a first elongate member having distal andproximal ends and having a tubular body having a lumen with an exteriordiameter; a second elongate member having distal and proximal ends andhaving a first region with an exterior diameter less that the interiordiameter of the lumen of the tubular body, the first region beingslideably received in the lumen of the tubular body; and a functionalelement carried by the second elongate element, the functional elementbeing expandable from a delivery configuration to an expanded deployedconfiguration when the functional element is deployed in the body lumen.

In a seventh embodiment, this invention is a method of occluding bloodflow through the lumen of a vessel during a percutaneous procedureperformed with a treatment device at a treatment site in the vesselcomprising providing a distal protection device including a guidewirehaving first and second elongate members and an occlusive device carriedby the second elongate member, the occlusive device being expandablefrom a delivery configuration to a deployed configuration, the firstelongate member being connected to the second elongate member in amanner that permits the first elongate member to be moved with respectto the second elongate member over a range of motion without moving thesecond elongate member; introducing the guidewire and the occlusivedevice in its delivery configuration into the lumen of the vessel;advancing the guidewire through the vessel until the occlusive device ispositioned at a desired location distal to the treatment site, at leasta proximal portion of the first elongate member extending outside of thevessel; expanding the occlusive device to its deployed configuration toocclude the lumen of the vessel; advancing the treatment device over theguidewire to the treatment site while holding the first elongate member;and performing the percutaneous procedure at the treatment site with thetreatment device while the lumen of the vessel is occluded.

In an eighth embodiment, this invention is a distal protection devicefor use in a body lumen comprising an elongate member having distal andproximal ends and having at least one longitudinal groove having distaland proximal ends; and a functional element carried by the elongatemember, the functional element being expandable from a deliveryconfiguration to an expanded deployed configuration when the functionalelement is deployed in the body lumen, the functional element having atleast one projection sized to be accommodated within the groove andconfigured to be slideable within the groove between the distal andproximal ends of the groove.

In a ninth embodiment, this invention is a method of making a guidewiresystem for delivery of a functional element to a desired location in abody lumen comprising providing a first elongate member, a secondelongate member and a functional element; mounting the functionalelement on the second elongate member; and connecting the first elongatemember to the second elongate member in a manner that permits the firstelongate member to be moved with respect to the second elongate memberwithout moving the second elongate member.

In a tenth embodiment, this invention is a method of filtering embolifrom blood flowing through the lumen of a vessel during a percutaneousprocedure performed with a treatment device at a treatment site in thevessel comprising providing a distal protection device including aguidewire having first and second elongate members and a filter carriedby the second elongate member, the filter being expandable from adelivery configuration when the filter is restrained to an expandeddeployed configuration when the filter is unrestrained, the firstelongate member being connected to the second elongate member in amanner that permits the first elongate member to be moved with respectto the second elongate member over a range of motion without moving thesecond elongate member; introducing the guidewire and filter in itsdelivery configuration into the lumen of the vessel; advancing theguidewire through the vessel until the filter is positioned at a desiredlocation distal to the treatment site, at least a proximal portion ofthe first elongate member extending outside of the vessel; removing therestraint on the filter to expand the filter within the lumen of thevessel to its expanded deployed configuration; advancing the treatmentdevice over the guidewire to the treatment site while holding the firstelongate member; performing the percutaneous procedure at the treatmentsite with the treatment device; and filtering emboli from blood duringthe percutaneous procedure with the filter.

In an eleventh embodiment, this invention is a distal protection devicefor use in a body lumen comprising an elongate member having distal andproximal ends and at least one stop spaced proximally of the distal end;a functional element having a first slider disposed for translationalong the elongate member between the stop and proximal end, the stoplimiting translation of the slider in a distal direction; and means forgradually increasing the resistance between the slider and stop as thestop is moved proximally toward the slider.

The functional element may comprise a second slider disposed fortranslation along the elongate member between the stop and distal end,the stop limiting translation of the second slider in a proximaldirection and wherein the means for increasing resistance includes meansfor gradually increasing the resistance between the second slider andthe stop as the stop is moved distally toward the second slider. Themeans for increasing resistance may include a spring, an elastomerictube, or first and second magnets having like-magnetic facing poles.

In a twelfth embodiment, this invention is a distal protection devicefor use in a body lumen comprising a first elongate member having distaland proximal ends; a second elongate member having distal and proximalends; a functional element carried by the second elongate element, thefunctional element being expandable from a delivery configuration to anexpanded deployed configuration when the functional element is deployedin the body lumen; and means for moveably connecting the filter and thefirst elongate member over a range of motion from a first relativeposition when the connecting means is in a relaxed state to a secondrelative position when the connecting means is in an expanded state suchthat resistance to movement between the filter and the first elongatemember increases over the range of motion as the second relativeposition is approached.

In a thirteenth embodiment, this invention is a distal protection devicefor use in a body lumen comprising a first elongate member having distaland proximal ends; a second elongate member having distal and proximalends; a functional element carried by the second elongate element, thefuinctional element being expandable from a delivery configuration to anexpanded deployed configuration when the functional element is deployedin the body lumen; and means for locking the first elongate member tothe second elongate member, the locking means having a locked positionwhere the relative positions of the first and second elongate membersare locked and an unlocked position where the first elongate member canbe moved over a range of motion from a first relative position to asecond relative position without resulting in movement of the secondelongate member.

In a fourteenth embodiment, this invention is a method of filteringemboli from blood flowing through the lumen of a vessel during apercutaneous procedure performed with a treatment device at a treatmentsite in the vessel comprising providing a distal protection deviceincluding a guidewire having first and second elongate members and afilter carried by the second elongate member, the filter beingexpandable from a delivery configuration when the filter is restrainedto an expanded deployed configuration when the filter is unrestrained;locking the first elongate member to the second elongate member so thattheir relative positions are fixed; introducing the guidewire and filterin its delivery configuration into the lumen of the vessel; advancingthe guidewire through the vessel until the filter is positioned at adesired location distal to the treatment site; removing the restraint onthe filter to expand the filter within the lumen of the vessel to itsexpanded deployed configuration; unlocking the first elongate memberfrom the second elongate member so that the first elongate member ismoveable with respect to the second elongate member over a range ofmotion from a first relative position to a second relative positionwithout resulting in movement of the second elongate member; advancingthe treatment device over the guidewire to the treatment site after thefirst elongate member has been unlocked from the second elongate member;performing the percutaneous procedure at the treatment site with thetreatment device; and filtering emboli from blood during thepercutaneous procedure with the filter.

In a fifteenth embodiment, this invention is a method of occluding bloodflow through the lumen of a vessel during a percutaneous procedureperformed with a treatment device at a treatment site in the vesselcomprising providing a distal protection device including a guidewirehaving first and second elongate members and an occlusive device carriedby the second elongate member, the occlusive device being expandablefrom a delivery configuration to an expanded deployed configuration;locking the first elongate member to the second elongate member so thattheir relative positions are fixed; introducing the guidewire andocclusive device in its delivery configuration into the lumen of thevessel; advancing the guidewire through the vessel until the occlusivedevice is positioned at a desired location distal to the treatment site;expanding the occlusive device to its expanded deployed configuration toocclude the lumen of the vessel; unlocking the first elongate memberfrom the second elongate member so that the first elongate member ismoveable with respect to the second elongate member over a range ofmotion from a first relative position to a second relative positionwithout resulting in movement of the second elongate member; advancingthe treatment device over the guidewire to the treatment site after thefirst elongate member has been unlocked from the second elongate member;and performing the percutaneous procedure at the treatment site with thetreatment device while the lumen of the vessel is occluded.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 to 4 are schematic views of various embodiments of the distalprotection device of this invention illustrating features which allowfor the guidewire to be moved independently of the functional element.

FIG. 5 is a schematic view of a further embodiment wherein the guidewireis provided with a telescoping structure allowing it to moveindependently of the functional element.

FIG. 6A is a schematic view of an alternate embodiment of the device ofthis invention having a slotted guidewire and FIG. 6B is across-sectional view along line B-B of FIG. 6A.

FIG. 7A is a further embodiment having first and second guidewires in asleeve, and FIGS. 7B and 7C are detail views of two additionalembodiments.

FIG. 8A is a schematic view of an alternate embodiment having first andsecond guidewires in a sleeve within the filter, and FIG. 8B is a detailview of FIG. 8A.

FIGS. 9, 10A, and 10B are schematic views of alternate embodiments ofthe device of this invention wherein independent movement of theguidewire is provided by various eyelet arrangements.

FIGS. 11, 12, 13A, 13B, and 13C are schematic views and partialcross-sectional views of alternate embodiments of the device of thisinvention where independent guidewire movement is provided by movementof a first completely or partially hollow guidewire with respect to asecond guidewire upon which the functional device is mounted.

FIG. 14A is a schematic view of a device similar to the embodiment ofFIG. 11 but where the functional element is a balloon and the guidewireis provided with a valve and an inflation lumen. FIGS. 14B and 14C arepartial cross-sectional views of the device of FIG. 14A.

FIGS. 15A to 15C and 16 to 18 are schematic views of alternateembodiments of the distal protection device of this invention showingvarious brake configurations.

FIGS. 19 to 27 are schematic views of various alternate embodiments ofthe distal protection device of this invention equipped with a shockabsorber feature. FIG. 26B is a detailed lengthwise cross-sectional viewshowing an alternative embodiment to that of FIG. 26A.

FIG. 28A is a schematic view and partial cross-sectional views of analternate embodiment of the device of this invention having a guidewirelocking feature. FIGS. 28B, 28C and 28D are cross-sectional views takenalong lines B-B, C-C, and D-D, respectively of the device of FIG. 28A.

FIG. 29A is a schematic view of a further alternate embodiment of thedevice of this invention having a guidewire locking feature. FIG. 29B isa partial view showing detail of the device of FIG. 29A; and FIG. 29C isa cross-sectional view along line C-C in FIG. 29B.

FIG. 30A is a schematic view and a partial cross-sectional view ofanother alternate embodiment of the device of this invention having aguidewire locking feature. FIG. 30B is a partial schematic view of aportion of the device of FIG. 30A.

FIG. 31A is a schematic view of a further alternate embodiment of thedevice of this invention having a guidewire locking feature. FIG. 31Band 31C are cross-sectional views of the device of FIG. 31A along linesB-B and Cam, respectively, and FIG. 31D is a planar cross-sectionalview.

FIGS. 32 to 35 are schematic and partial cross-sectional views of stillfurther alternate embodiments of the device of this invention equippedwith a guidewire locking feature.

FIG. 36A is a schematic view of a further alternate embodiment of thedevice of this invention having a guidewire locking feature and FIGS.36B and 36C are cross-sectional views of the device of FIG. 36A alongline B-B.

FIG. 37 is a perspective view of a Prior Art distal protectionfiltration device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Various embodiments of the invention are disclosed herein. Some of theembodiments are directed to devices that allow independent movement ofthe guidewire with respect to the filter or other functional elementonce the functional element has been deployed. (FIGS. 1-14). Otherembodiments are directed to devices having a braking feature. (FIGS.15-18). Brakes provide a means to cushion the force when a wire, movingwith very low friction relative to a filter, encounters a stop. Thebrake provides tactile feedback that the hard stop is approaching, andthis tactile feedback allows the doctor to adjust the motionaccordingly. Other embodiments include a shock absorbing feature, (FIGS.19-27). Shock absorbers act as distance-accommodating springs that arenot frictionally independent from the wire. Both allow feedback to thephysician so the physician can avoid dislodging or disrupting thefunctional device by excessive movement of the guidewire carrying thedevice during a vascular procedure.

Still other embodiments incorporate a locking feature that can beengaged or disengaged. (FIGS. 28-36). When engaged, the relativeposition of the functional device and guidewire is locked to allowaccurate positioning and deployment of the functional device and, ifdesired, retrieval of the device. When the locking feature isdisengaged, the guidewire can be moved independently of the device toallow some movement of the guidewire during, for example, catheterexchanges over the guidewire without dislodging or disrupting thefunctional device.

The terms “distal” and “proximal” as used herein refer to the relativeposition of the guidewire, catheters, and distal protection system in alumen. Thus, “proximal” refers to a location upstream from the “distal”position. That is, the flow of a body fluid, such as blood, moves fromthe proximal to the distal portions of the device of this invention.

The various embodiments of distal protection systems of this inventionare meant to encompass the use of any functional device to be deployedin a lumen or vessel of a patient in a minimally invasive procedure. Itis to be understood that the devices described and illustrated below, inwhich the motion of the distal protection device relative to a guidewireis controllable by various means, applies to occlusive devices,filtration devices, and any other functional device where it is usefulto allow limited movement and/or tactile feedback between the device anda guidewire that carries the device. Many of the embodiments show thefunctional device in the form of a filter having a windsock type shape.(See FIGS. 1, 3-12, 15-17, 19-22, and 25-36). The construction,deployment and retrieval of such a filter is described, for example, inU.S. Pat. No. 6,325,815 (Ser. No. 09/400,159, Kusleika et al.), which isincorporated by reference herein in its entirety. Other of theembodiments show the filter as a cup shaped device which forms aproximally facing opening when expanded. The construction, deploymentand retrieval of such a filter is described in WO 96/01591 (Mazzochi etal.), which is incorporated by reference herein in its entirety. Instill another embodiment the functional element is an occlusive deviceshown as a balloon. (FIG. 14). It will be understood however, that othertypes of occlusive devices may be used. For example, the various filtersshown herein could be made into occlusive devices if the filter meshwere coated with a polymer. Additionally, an occlusive device could beformed from any substantially rigid support frame coated with flexibleocclusive material. The occlusive material may be sheets or films ofpolymer, urethane, silicon, latex, rubber, or thin films of anengineered polyurethane such as polyester or nylon. The thin films maybe biaxially oriented. It will be appreciated that these functionaldevices shown in the various embodiments are merely illustrative and arenot meant to limit the scope of the invention.

Typically the distal protection system is introduced into a blood vesselthrough an introducing catheter. Methods of introducing guidewires andcatheters and the methods for the removal of such devices from vesselsare well known in the art of endovascular procedures. In a typicalprocedure using the device of this invention, the guidewire, thefunctional element which can be a filter or occlusive device, and themeans for controlling the movement of the functional element all areloaded into an introducing sheath or catheter and moved into the vesselto the treatment site. This is done typically by moving the introducingsheath or catheter along a first, or introduction guidewire, which wasput in place as the first step of the procedure at the region ofinterest. The sheath or catheter is advanced over the guidewire to theregion of interest, and the guidewire removed. Then the functionalelement on a wire is advanced down the catheter to the region ofinterest but within the catheter or sheath. The catheter is withdrawn todeploy (expand) the functional element at the region of interest. If thefunctional element is a filter, the filter captures emboli releasedduring the procedure by the treatment device which has been advancedover the guidewire. When the procedure is complete, the filter isretracted to a reduced removal configuration and removed from the vesselalong with the guidewire.

Alternatively, if the functional element is self-expanding, it may bepreloaded into a catheter and held in place by means of the catheter andthey are together advanced through the vessel to the region of interestwithout using an initial guidewire. If the functional element is notself-expanding, such as a balloon or other structure requiringactivation to be expanded, then the functional element can be collapsed,advanced to the treatment site, and expanded without the use of acatheter. If the functional element is an occlusive device, during orafter the conclusion of the procedure, aspiration through a lumen of acatheter is performed before flow is restored in the body lumen bycontracting the occlusive device to its removal configuration.

Typical dimensions of a filter used in the devices of this inventionrange from 2 mm to 90 mm in length, and from about 1 mm to 2 mm indiameter before deployment, and about 2 mm to 30 mm in diameter afterdeployment. A typical guidewire is about 0.3 to 1.0 mm in diameter andranges from 75 cm to 320 cm in length.

The distal protection device comprises biocompatible materials.Materials also may be surface treated to produce biocompatibility. Theguidewire may be formed of any material of suitable dimension andfunctional characteristics, and generally comprises metal wire.Preferably the materials are partly or completely radiopaque. Theguidewire may be solid or may be hollow over some or all of its length.

The material used to make the filter preferably is self expanding. Thiscan be accomplished by using self-expanding materials. These materialsinclude metals such as stainless steel, titanium and its alloys,cobalt-chromium-nickel-molybdenum-iron alloy (commercially availableunder the trade designation Elgiloy™), and engineered polymers such asliquid crystal polymers, polyetheretherketone (PEEK), polyimide,polyester, silk, and the like. A shape memory metal is particularlysuitable for those applications when it is desired for an element, suchas a filter, to assume a pre-determined three dimensional shape or for aguidewire to maintain a pre-determined curvature. A shape memory metalcomprising nickel and titanium is commercially available under the tradedesignation “Nitinol” in various dimensions and is suitable for use asboth a guidewire and a filter. For example, nitinol tubular braid can beheat set into a desired shape, compressed for delivery to a site, andthen released to form the heat-set shape.

The filter may comprise any material that is suitably flexible andresilient, such as a mesh. The filter may comprise braided, knitted,woven, or non-woven fabrics. Non-woven fabrics may additionally betreated to fuse some or all of the fiber intersections. The fabric maybe electrospun. Suitable material includes that formed from sheets orfilms, polymeric or metallic, with holes formed by mechanical means suchas laser drilling and punching, or by chemical means such as selectivedissolution of one or more components. For example, a suitable filtermaterial is braided tubular fabric comprising nitinol shape memorymetal. Mesh fabric of nitinol material can be heat-set to a desiredshape in its expanded configuration. The filter material is preferablyat least partially radiopaque. The filter material can be maderadiopaque by plating, or by using core wires, tracer wires, or fillersthat have good X-ray absorption characteristics compared to the humanbody.

In some embodiments of the filter, fixed or slideable elements at theends of the filter are discussed. These slideable elements may compriseinner and outer annular rings. (Not shown in the FIGS.). The first ringfits within the second ring. The inner diameter of the first ring islarger than the diameter of the guidewire so that the sliding elementcan slide over the guidewire. The sliding element can be affixed to thefilter fabric by placing the fabric between the first and second rings.However, this is not meant to be limiting, and the fabric can also beaffixed to the slideable element by adhesive, solder, crimping, or othermeans known in the art. The slider may comprise any stiff material suchas metal or polymer and preferably the slider is radiopaque. Suitablematerials include stainless steel, titanium, platinum, platinum/iridiumalloy, gold alloy, polyimide, polyester, polyetheretherketone (PEEK),and the like.

By “fixed element” is meant an element that is attached to the guidewireand does not move independently of it. The fixed element may be anannular ring but also included within this meaning is an element that iscrimped, adhered, soldered, or otherwise fastened directly to theguidewire. In any event, the sliding or fixed elements typicallycomprise radiopaque material to assist in the placement of the filter.

Movement of a sliding element with respect to the guidewire can befacilitated by coating one or both of the inside of the sliding elementand the outside of the guidewire with a friction-reducing coating, suchas polytetrafluoroethylene (commercially available under the tradedesignation Teflon™) or a lubricious hydrophilic coating.

Spring elements disclosed in some of the embodiments are composed ofmetal, polymer, or combination of the two. Suitable materials includestainless steel, Nitinol, spring steel, Elgiloy, polyimide, PEEK,oriented polymer filaments, metal reinforced polymers, rubbers,polyurethanes, silicones, and the like.

Some embodiments include a “floppy tip” at the distal end of the device.The floppy tip provides an atraumatic and radiopaque terminus for thedevice. An atraumatic tip prevents vessel injury during initialplacement or subsequent advancement of the device. A radiopaque tiphelps the physician verify suitable tip placement during fluoroscopy.The floppy tip preferably comprises a springy or resilient material,such as a metal (e.g., stainless steel, iron alloys such as Elgiloy™,and shape memory metal such as Nitinol) or polymer (e.g.,polyetheretherketone (PEEK), polyimide, polyester,polytetrafluoroethylene (PTFE), and the like). Springy materials aredesirable because they tend to retain their shape. The physician willinitially ‘shape’ the tip, typically with a slight curve, and then asthe wire is advanced through the body the tip will be deflected as itencounters obstacles. It is desirable, after the inevitable deflectionsduring insertion, that the tip restore itself to the pre set shape.Polymeric materials additionally may be reinforced with metals or otherfillers. The material may be a monofilament or multifilament (such as acable). The floppy tip may be tapered or have a uniform diameter overits length. The floppy tip could comprise a tube, or could havecircular, flat, or other cross-sections. It could be coiled. The tipcould comprise one or more elements (i.e., parallel independentstructures). The tip may be polymer-coated or otherwise treated to makethe surface slippery. The floppy tip can be any desired length.

Other elements of the filtration device also comprise biocompatiblematerials, and these include metals and polymeric materials. Thesematerials can be treated to impart biocompatibility by various surfacetreatments, as known in the art. When wire is used, the wire is selectedon the basis of the characteristic desired, i.e., stiffness orflexibility, and the properties can depend upon both the diameter of thewire and its cross-sectional shape. The size-, thickness and compositionof elastic materials are selected for their ability to perform asdesired as well as their biocompatibility. It is to be understood thatthese design elements are all within the scope of this invention.

The various embodiments of the invention will now be described inconnection with the drawing figures. It should be understood that forpurposes of better describing the invention, the drawings have not beenmade to scale. Further, some of the figures include enlarged ordistorted portions for the purpose of showing features that would nototherwise be apparent.

Wire Motion

FIGS. 1-14 illustrate embodiments in which there is independent motionallowed between the filter and an elongate guide member such as aguidewire. This can be done by various sliding interlocking wirearrangements, tethers with overlying slideable tube arrangements, andthe like. The independent wire motion permits the wire to move withoutdisturbing filter position, and this carries all of the advantagesdescribed above.

FIG. 1 is a schematic view of filter 10, proximal element 14, and distalslider element 16 disposed about a first guidewire 12. Proximal element14 is attached to flexible wire 15 (preferably having a narrowdiameter), which itself is crimped or by other means attached to secondguidewire 13 at region 11. Guidewire 13 is shown emerging from thedistal end of catheter C. Catheter C is shown generically and may be adelivery catheter and/or a retrieval catheter. Catheter C is shown onlyin FIG. 1 and is not repeated in the other drawing figures since it willbe appreciated that a catheter is used to deliver and retrieve theembodiments disclosed herein. For purposes of clarity, the filter 10 andthe other filter and device embodiments disclosed herein are shown onlyin outline so that other details of the invention are more easilyunderstood. The length of flexible wire 15 between the distal end ofguidewire 13 and the fixed proximal element 14 permits movement ofguidewire 13 (indicated by the arrows) without causing axial movement ofthe filter. Further, because of the flexibility of the tether, wire biasis decoupled from the filter, leading to excellent radial independenceof filter position relative to wire motion.

FIG. 2 is a schematic view of filter 20, proximal element 24, and distalslider element 26 disposed about guidewire 22. The guidewire endsdistally at floppy tip 23. Floppy tip 23 is provided as an atraumaticand radiopaque terminus for the filter. The tip comprises any suitablyflexible and springy material, as discussed above. Wire 22 extendsproximally to stop 25 which is configured to fit within the core ofhollow guidewire 27. Guidewire 27 may be hollow along its entire lengthor only along a distal portion sufficient to accommodate wire 22.Restriction 29 at the distal end of this hollow wire provides a stoppingmechanism for movement of the filter. Once filter 20 is deployed withina vessel, guidewire 27 may be moved independently of filter 20 by anamount limited only by the distance between stop 25 and proximal element24.

FIG. 3 is a schematic view of a filter 30, proximal fixed element 34,and distal slider element 36 disposed about wire 32. Wire 32 has anenlarged proximal end 37. Hollow guidewire 39 (shown in cross section asindicated by cross hatching) contains recess 33, which slideablyreceives a proximal portion of wire 32 including enlarged end 37. Hollowguidewire 39 has restriction 38 at its distal end to prevent enlargedend 37 from exiting recess 33. Restriction 38 is sized to allow slidingmotion of the proximal portion of wire 32. Hollow guidewire 39 alsocontains step 31 at the proximal end of recess 33 to limit the proximalmovement of enlarged end 37. Hollow guidewire 39 may be hollow over itsentire length or may be hollow over only the distal portion includingrestriction 38 and step 31. Once filter 30 is deployed within a vessel,guidewire 39 may be moved independently of filter 30 by an amountlimited only by the distance between step 31 and restriction 38.

FIG. 4 is a schematic view of an embodiment similar to that shown inFIG. 2. Filter 40 and distal fixed element 46 are disposed about wire42. Wire 42 ends distally at floppy tip 43. Wire 42 extends proximallyto stop 45 configured to fit within the core of hollow guidewire 47.Proximal slider element 44 (shown in cross section as indicated by crosshatching) is disposed about hollow guidewire 47. Guidewire 47 extendsinto the filter. Restriction 49 at the distal end of guidewire 47provides a stopping mechanism to ensure that stop 45 is retained withinguidewire 47. In this embodiment, guidewire 47 may move independently ofthe filter by an amount equal to the distance between stop 45 and distalelement 46. Filter length may be longer than the length of independentwire motion. Alternatively filter length can be shorter than the lengthof independent wire motion by suitable tapering of restriction 49 toallow for unimpeded motion of slider 44 over restriction 49.Alternatively, optional stop 41 (shown in cross section as indicated bycross hatching) may be added to limit the distal axial motion ofproximal slider element 44.

FIG. 5 is a schematic view of filter 50, proximal fixed element 54, anddistal slider element 56 disposed about wire 52. Wire 52 extendsproximally through one or more hollow guidewires. Two guidewires, shownhere as 59 a and 59 b, are illustrated in the figure and are shown incross section as indicated by cross hatching. Wire 52 is provided withproximal retaining element 55. Hollow guidewires 59 a and 59 b haveproximal retaining elements 57 a and 57 b, respectively, and distalretaining elements 58 a and 58 b, respectively. These retaining elementsmay be a continuous annular projection disposed on the hollowguidewires, as shown, or they may be discontinuous. Hollow guidewires 59a and 59 b slideably cooperate in a telescoping fashion, with theretaining elements 57(a andb) and 58 b serving to limit the relativemotion of these wires. The motion of proximal retaining element 55 onwire 52 is restrained by retaining elements 55 a and 55 b on the insideof hollow guidewire 59 a. The hollow guidewire optionally could betapered at its distal end (i.e., nearer the filter), similar to thetaper shown in the embodiment of FIG. 3. This device permits movement ofthe guidewire while the filter remains stationary a distance equal tothe distance between retaining element 55 and proximal element 54 plusthe distance between proximal retaining element 57 b and distalretaining element 58 b.

FIG. 6A is a schematic view of filter 60, proximal slider element 64,distal slider element 66, disposed about guidewire 62 having floppydistal tip 63. The drawing shows the slider elements in cross-section(as indicated by cross-hatching), disposed about guidewire 62, whosescale is exaggerated for this drawing. Guidewire 62 may be hollow orsolid and has one or more longitudinal grooves or slots (slot 65 isshown) that slideably receive tangs 67 emanating from the internaldiameter of either slider element or both. In the embodiment of FIG. 6A,the tangs extend from slider 64. FIG. 6B shows a cross-section alongline B-B of slider element 64 having tangs 67 engaging two slots 65 inguidewire 62. Thus the motion of the filter along the guidewire iscontrolled by the length of slot 65 and the movement of slider element64 in cooperation with it.

FIG. 7A is a schematic view of filter 70, proximal fixed element 74, anddistal slider element 76 disposed about first guidewire 72. Guidewire 72extends proximally to proximal stop 73 through sleeve 75. Sleeve 75 maycomprise metal or polymeric material and may be cylindrical or may havechamfered ends. Second, interlocking guidewire 77 with optional stop 78extends through the sleeve from the proximal direction to distal stop79. Guidewires 72 and 77 extend through sleeve 75 through one or morelumens sized to accommodate the guidewires but to block passage of stops73, 78, and 79 and proximal fixed element 74. Specifically, in FIG. 7A,sleeve 75 has lumens 72 a and 77 b to accommodate guidewires 72 and 77,respectively. In this embodiment, guidewire 77 can move independently offilter 70 by an amount equal to the distance between stops 78 and 79less the length of the sleeve plus the distance between stop 73 andproximal element 74 less the length of the sleeve.

FIGS. 7B and 7C show partial detail cross sectional views of the sleeveportion. A single lumen 71 accommodates both guidewires. In FIG. 7B, therounded balls that form stops 73 and 79 are aligned with the axis of theguidewires, while in FIG. 7C, they are offset to facilitate clearanceand movement of the guidewires through the lumen. In FIG. 7B, guidewire72 b extends through sleeve 75 b to stop 73 b; guidewire 77 b extendsthrough sleeve 75 b to stop 79 b. Similarly, FIG. 7C shows guidewire 72c extending through sleeve 75 c to stop 73 c and guidewire 77 cextending through sleeve 75 c to stop 79 c.

FIGS. 8A and 8B show an embodiment similar to FIG. 7A, wherein theguidewires pass through a sleeve which is located inside the filter.Filter 80 and proximal slider element 84 are disposed about firstguidewire 87. Filter 80 and distal slider element 86 are disposed aboutsecond guidewire 82. Guidewire 87 extends from the proximal directioninto the filter and terminates at stop 89. Guidewire 82 extends from thedistal direction into the filter and terminates at stop 81. Guidewires87 and 82 extend through sleeve 85, located within the filter, throughone or more lumens (81 a and 89 a) sized to accommodate guidewires 82and 87 but to block the passage of stops 81and 89. In addition,guidewire 82 terminates at floppy tip 83 at its distal end. Sleeve 85helps to stabilize and control motion of the two guidewires with respectto one another. This embodiment allows for independent motion ofguidewire 87 with respect to filter 80 in a manner similar to thatdescribed with respect to FIG. 7A.

FIG. 9 is a schematic view of an interlocking eyelet arrangement. Thisembodiment has filter 90, proximal slider element 94, and distal sliderelement 96 disposed about proximal guidewire 91 having interlockingeyelet 91 a and distal guidewire 92 having interlocking eyelet 92 a.Eyelet 91 a is disposed about guidewire 92 and eyelet 92 a is disposedabout guidewire 91. In addition, this embodiment is equally functionalif slider element 96 is fixed. Independent wire motion is achieved bythe eyelets sliding over the wires while the wire(s) slide through theslider element(s).

FIG. 10A illustrates a filtration device in which a snare loop 103 a, atthe distal end of first guidewire 103, loops around a second guidewire102. Snare loops can be built according to the methods disclosed in U.S.Pat. No. 5,171,233 (Amplatz et al.). In FIG. 10A, proximal fixed element104 and distal slider element 106 are disposed about guidewire 102.Filter element 100 is disposed beside guidewire 102. Snare loop 103 apasses around guidewire 102 but does not pass through filter 100. InFIG. 10B, filter 100, proximal fixed element 104 and distal sliderelement 106 are disposed about second guidewire 102, and first guidewire103 has snare loop 103 b at its distal end. FIG. 10A illustrates snareloop 103 a outside filter 100 and FIG. 10B illustrates snare loop 103 bwithin filter 100. In either embodiment, the loop can move between thefixed proximal element and the distal sliding element to allowindependent movement of guidewire 103 with respect to filter 100 in thatamount.

FIG. 11 illustrates a schematic view and partial cross-sectional viewsof a filter 110, proximal fixed element 114, and distal slider element116 disposed about guidewire 112, which ends distally at floppy tip 113.Enlarged partial cross-sectional views show the shape of guidewire 112as it extends proximally through a second guidewire, which compriseshypotube 115. Guidewire 112 has a reduced diameter 111, which isslideably received within hypotube 115, and an enlarged end 118.Enlarged end may be only a few millimeters in length or optionally couldbe 100 cm long or more. Distal motion of hypotube 115 relative toguidewire 112 is limited by impingement of hypotube 115 distal end 115 aagainst step 117. Proximal motion of hypotube 115 relative to guidewire112 is limited by impingement of proximal end 115 b of hypotube 115against enlarged end 118. Chamfers are preferably incorporated in bothproximal and distal ends of hypotube 115, step 117, and proximal anddistal ends of enlarged end 118 to provide for smooth passage ofcatheters and the like over the assembly. Preferably, the diameter ofenlarged end 118, hypotube 115, and distal portion of guidewire 112 areapproximately equal and sized to be compatible with and allow deliveryof conventional catheters over hypotube 115. Guidewire 112 and hypotube115 are sized so that when the filter element is deployed distally of atreatment site the hypotube extends from a location inside the patientto a location outside of the patient. Alternatively, the hypotube may beentirely outside the patient. This allows the physician when makingexchanges to minimize filter movement while making the exchange. Anymotion of hypotube 115 during the exchange is not passed on to guidewire112 or filter 110 since hypotube 115 moves independently of both theguidewire and the filter. The embodiment of FIG. 11 has the advantage ofproviding for a very large amount of motion of hypotube 115 relative tofilter 110. Specifically, when catheter exchanges are made overguidewire 112 during a procedure, hypotube 115 can move independently ofguidewire 112/filter 110 by an amount equal to the distance between end118 and step 117 less the length of hypotube 115.

FIG. 12 illustrates a schematic view and enlarged partialcross-sectional view of filter 120, proximal fixed element 124, anddistal slider element 126 disposed about guidewire 122, which endsdistally at floppy tip 123. Partial cross-sectional views show the shapeof guidewire 122 as it extends proximally through the distal end of asecond guidewire comprising hypotube 125. Guidewire 122 has step 127,reduced diameter section 121, and enlarged proximal end 128. Hypotube125 has crimp 129 and distal restriction 125 a. Distal motion ofhypotube 125 relative to wire 122 is limited by impingement of hypotubedistal end 131 against step 127 or by impingement of crimp 129 againstenlarged end 128. Proximal motion of hypotube 125 relative to guidewire122 is limited by impingement of hypotube restriction 125 a againstenlarged end 128. Chamfers are preferably incorporated in proximal anddistal ends of hypotube 125 and step 127 to provide for smooth passageof catheters and the like. Preferably the diameter of hypotube 125 andproximal portion of guidewire 122 are approximately equal and sized tobe compatible with conventional catheters.

Alternative constructions of the embodiment of FIG. 12 are shown inFIGS. 13A to 13C, which illustrate partial cross-sectional views of theshape of guidewire 122 as it extends proximally into the distal end ofhypotube 125. In FIG. 13A, guidewire 122 a has step 127 a, reduceddiameter section 121 a, and enlarged proximal end 128 a. Hypotube 125 ais joined to a solid piece of material 135 a within the hypotube bymeans of soldering, welding, and the like. Material 135 a serves tolimit the distal movement of hypotube 125 a with respect to guidewire122 a. In FIG. 13B, guidewire 122 b has step 127 b, reduced diameter 121b, and enlarged proximal end 128 b. Hypotube 125 b is provided with acounterbore resulting in proximal step 135 b, which serves a functionsimilar to material 135 a in FIG. 13A. FIG. 13C illustrates guidewire122 c with step 127 c, reduced diameter 121 c, enlarged proximal end 128c, and two crimps 135 c and 136 c in hypotube 125 c. These crimps serveto limit the range of guidewire motion to the region between the twocrimps. This alternative construction differs from FIG. 12 in that thelength of tube 125 c distal to distal crimp is quite long so as topreserve axial alignment between tube 125 c and wire 122 c.

FIG. 14A is a schematic view of a balloon protection device whichprovides for relatively independent guidewire motion in the same manneras described for the embodiment of FIG. 11. The device is shown in crosssection. Balloon 140 is attached to hollow guidewire 142 at the distalend of the guidewire; floppy tip 143 extends distally from guidewire142, and balloon port 146 communicates between the guidewire lumen 142 aand the interior of the balloon. Guidewire 142 has reduced diameterportion 141, step 147, and enlarged end 148 that serve to restrict themotion of slideably coupled hypotube 145.

FIGS. 14B and 14C illustrate partial cross-sectional views of solidguidewire 144 within hollow guidewire 142. Solid guidewire 144 ismanipulated in an axial direction to open and close port 149. Theproximal end of hollow guidewire 142 communicates with port 149, whichis in fluid communication with balloon 140 through balloon port 146.Proximal solid guidewire 144 is slideably received within proximal endof hollow wire 142 and extends proximally beyond proximal end of wire142. When proximal solid guidewire 144 is retracted proximally relativeto hollow guidewire 142, port 149 is opened to allow a fluid to beinjected into port 149 causing balloon 140 to be inflated. When proximalsolid guidewire 144 is advanced distally relative to hollow guidewire142, the port is closed. Alternatively, port 149 can be located distalto hypotube 145. Alternatively, hypotube 145 can be slideably disposedon proximal solid wire 144. FIG. 14B shows that when the valve isclosed, port 149 is occluded by solid guidewire 144. FIG. 14C shows therelative position of guidewires 142 and 144 when the valve is open; port149 is not occluded.

Brakes

FIGS. 15 to 18 illustrate embodiments in which there is some form ofbraking feature included on the movement of the wire relative to thefilter (and, thus, of movement of the filter). This braking feature maybe accomplished by adding a compressible element or cooperating magnetsalong the guidewire within the filter, or by adding a brake eitherinside or outside of the filter to cooperate with any of the stops,distal restrictions, slot ends, or hypotube ends shown in the precedingfigures. The brake permits increased levels of tactile feedback to thephysician manipulating the guidewire. This tactile feedback enables theuser to determine the range of guidewire movement with respect to thefilter or other functional device carried by the guidewire. It should beunderstood that the various brake embodiments described herein may beincorporated into any of the previously described wire motionembodiments or into other known systems where there is a desire to limitthe relative motion between a functional element carried on a guidewire.

FIG. 15A is a schematic view of filter 150, guidewire 152, proximalslider element 154 a, distal slider element 156 a, and brake element 155a located within the filter. Brake element 155 a comprises spring 158 afastened to guidewire 152 at connection point 157 a. During theprocedure, wire motion may occur caused, for example, by exchange ofcatheters over the guidewire. As the wire is advanced proximally ordistally slider element 154 a or 156 a will contact an end of brakeelement 155 a. The physician will sense a gradually increasing wireresistance as the brake element is compressed with increasing wiretravel, and can use this sensation to avoid moving the wire excessivelyand thereby cause undesired movement of the filter. Brake element 155 amay comprise metal or polymeric material.

FIG. 15B is a schematic view of filter 150, guidewire 152, proximalslider element 154 b comprising a magnet or to which a magnet isattached, distal slider element 156 b comprising a magnet or to which amagnet is attached, and fixed element 158 b comprising a magnet or towhich a magnet is attached. Fixed element 158 b is attached to guidewire152 between the proximal and distal slider elements. The magnets areoriented such that a south pole of one slider magnet faces the southpole of the adjacent fixed magnet, and the north pole of the otherslider magnet faces the north pole of the adjacent fixed magnet (asdesignated by N and S in the drawing). As slider elements 156 b or 154 bapproach fixed element 158 b, there is a gradually increasing repulsiveforce due to the repulsion of like magnetic poles. Thus, the sliderswill tend not to make contact with the fixed element. The physician willsense a gradually increasing wire resistance as the magnets approacheach other with increasing wire travel, and can use this sensation toavoid moving the wire excessively and thereby cause undesired motion ofthe filter.

FIG. 15C is a schematic illustration of filter 150, guidewire 152,proximal slider element 154 c, distal slider element 156 c, and fixedelement 155 c located within the filter. Element 155 c comprises anelastomeric sleeve 157 c fused to guidewire 152 at connection point 158c. Either slider (154 c or 156 c) will contact an end of the sleeve, andthe tubing will progressively brake the motion of the slider bycompressing with gradually increasing force as the slider pressesagainst it. The embodiment of FIG. 15C has many of the same advantagesas those described for the embodiments of FIGS. 15A and 15B with respectto providing the physician with a sense of increasing resistance ifthere is excessive wire motion.

FIGS. 16 and 17 show embodiments incorporating a braking system, whereinrespectively, a filter (160 and 170) is attached to a tube (165 and 175)having a lumen (161 and 171) which slidingly accommodates guidewire (162and 172). The proximal end of the filter is fixed to the tube while thedistal end of the filter is connected to a sliding element (166 and 176,illustrated in cross section, as indicated by the cross hatches) whichslides over the tube. In FIG. 16, brakes 167 and 169 are positioned bothdistal and proximal of the tube on the guidewire. The brakes are shownas coil or spring elements of two different types. The same or differenttypes could be used in one device. Brake 167 is a coil attached to anddisposed about guidewire 162 and brake 169 is attached to the guidewireat point 169 a. In FIG. 17, only a distal brake 179 is shown. It will beappreciated that braking arrangements as disclosed in FIGS. 15B and 15Care equally applicable to the embodiments of FIGS. 16 and 17.

FIG. 18 is a partial cross-sectional view that shows brake principlessimilar to those discussed in connection with FIG. 15 to 17 but appliedto wire motion permitting embodiments such as those described in FIG. 11and FIG. 14. Hypotube 185 is disposed over wire 182 and is equipped withbrake elements 189 at both the proximal and distal ends of proximalhypotube 185. Distal translation of hypotube 185 will result inprogressive engagement of brake element 189 with step 187. Proximalmotion of the hypotube 185 will similarly result in progressiveengagement of the proximal brake 189 with enlarged end 183. Brakeelement 189 can be composed of a coil spring, an elastomer, a magnet(having a corresponding magnet on the opposing face, e.g., step 187),and other devices and materials that can function as a brake.

Brakes can be similarly applied to the embodiments shown in FIGS. 2 to9, 10A and 10B, 12, and 13 by those of ordinary skill in the art. Forexample, brake elements can be applied to the distal end of stop 25 andproximal end of restriction 29 in FIG. 2. A tubular brake can besubstituted for or applied to both ends of sleeve 75 in FIGS. 7A to 7C.A brake can be interspersed between the interlocking eyelets (92 a and91 a) in FIG. 9 or between the snare loop (103 a/103 b) and proximalband 104 in FIG. 10A

Shock Absorbers

FIGS. 19 to 27 illustrate embodiments which incorporate a shock absorberfeature. A shock absorber is used in embodiments where there is aphysical connection between a functional device such as a filter and aguidewire. The physical connection limits relative movement between thefilter and the guidewire. The shock absorber is incorporated into thephysical connection to provide increasing resistance as the wire ismoved with respect to the filter. The shock absorber feature providestactile feedback to the physician concerning the extent of guidewiremotion relative to the filter. The shock absorbers permit comparativelyindependent motion of the guidewire relative to the filter.

FIG. 19 is a schematic illustration of a distal protection devicecomprising filter 190, proximal fixed element 194, and distal sliderelement 196 disposed about guidewire 192. Proximal fixed element 194 isattached to flexible tether 198. Tether 198 is attached at its proximalend to a shock absorber comprising a spring element 195 which itself isattached within a hollow core 193 of a second (host) guidewire 197(shown in cross section, as indicated by cross hatching). In use thespring element 195 manages the tether 198 so that excess tether iswithdrawn into hollow core 193 of the second guidewire 197. Thisembodiment allows for relatively independent movement of guidewire 197after filter 190 has been deployed. Spring 195 also serves to providethe physician with a sense of increasing wire resistance if theguidewire is withdrawn too far proximally. Further, because of theflexibility of the tether, wire bias is decoupled from the filter,leading to excellent radial independence of filter position relative towire motion.

FIG. 20 is a schematic illustration of a filtration device of thisinvention comprising filter 200, proximal slider element 204 (disposedat the proximal end of the filter) and distal fixed element 206(disposed at the distal end of the filter) disposed about guidewire 202.The slider element is configured to move freely over the guidewire. Ashock absorber comprising a spring element 205 has a first end connectedto distal fixed element 206 and a second end connected to guidewire 202at point 207. Spring element 205 may be integrally formed from theguidewire or may be a separate element affixed to the guidewire. Somemotion of the proximal end of wire 202 in either a proximal or distaldirection will be accommodated without moving filter 200 by increasingor decreasing compression of spring element 205. Filter 200 will exhibitsome resistance against the vessel wall in order to resist axial motionof guidewire 202 as transmitted through spring element 205. Thus,movement of the filter will not be caused unless guidewire movement isexcessive.

FIG. 21 is a schematic illustration of filter 210, proximal sliderelement 214 and distal fixed element 216 disposed about guidewire 212.Affixed to the filter's distal end 217 is spring element 215, which isattached to distal fixed element 216. Spring element 215 may be formedintegrally with filter 210 or may be a separate component attached todistal end 217 and distal fixed element 216. Optionally, a distal slidercan be incorporated at distal end 217 of the filter. Motion of theproximal end of wire 212 will be accommodated without moving filter 210by increasing or decreasing compression of spring element 215. Filter210 will exhibit some resistance against the vessel wall in order toresist axial motion of guidewire 212 as transmitted through springelement.

FIG. 22 is a schematic illustration of filter 220, proximal fixedelement 224, and distal slider element 226 disposed about guidewire 222.Near the proximal end of filter 220, a shock absorber comprising braid225 is attached to guidewire 222 at connection point 227 oralternatively to proximal fixed element 224. This connection point canbe relatively close to proximal fixed element 224 (i.e., millimeters) orcould be farther away (i.e., centimeters). Braid 225 is itself attachedproximally to second guidewire 229. Braid 225 may be any desired length,preferably between about 10 to about 40 cm. Alternatively, shockabsorber 225 could be a coil wound with spaces between adjacent coilwindings. The braid in this embodiment is configured to lengthen orshorten to accommodate motion of second guidewire 229 without disturbingthe filter placement. Further, because of the radial flexibility of thebraid, wire bias is decoupled from the filter, leading to excellentradial independence of filter position relative to wire motion.

FIG. 23 is a schematic illustration of filter 230, proximal fixedelement 234 and distal slider element 236 disposed about a firstguidewire 232. The guidewire 232 ends distally at floppy tip 233 whichprovides an atraumatic and radiopaque terminus for the filter.Proximally, guidewire 232 is attached to elastomeric sleeve 235 which isattached proximally to a second guidewire 237, the distal end 238 ofwhich is shown inside of elastomeric sleeve 235. Elastomeric sleeve 235may be attached directly to guidewire 232 proximal to or at proximalfixed element 234. The elastomeric tube 235 can lengthen or shorten toaccommodate wire 237 motion without disturbing the filter placement. Theradial flexibility of the elastomeric sleeve decouples wire bias fromthe filter, leading to excellent radial independence of filter positionrelative to wire motion. Elastomeric tube 235 can be any desired length,preferably between about 10 to about 40 cm.

FIG. 24 is a schematic illustration of filter 240, proximal sliderelement 244, and distal slider element 246 disposed about guidewire 242.The guidewire ends distally at “floppy tip” 243. At the distal end ofthe filter, coil shock absorber 245 is attached to the distal element246 proximally and to guidewire 242 distally at attachment point 247.Shock absorber 245 can be attached by any suitable means includingwelding or adhesives and serves to dampen the motion of the filterrelative to the motion of the guidewire.

FIG. 25 is a schematic illustration of an embodiment with similaritiesto the embodiment of FIG. 24. Filter 250, and proximal slider element254 are disposed about guidewire 252. Distal fixed element 256 isdisposed about wire tip 253. The guidewire 252 ends distally at coilshock absorber 255. The distal end of the filter 250 is attached tofixed element 256, to which is attached floppy tip 253 and also withinfilter 250 is attached shock absorber 255. Shock absorber 255 may bemetallic or polymeric braid or coil, or an elastomeric material. Itserves to damp the motion of the filter 250 relative to wire 252 in theproximal and distal directions.

FIG. 26A is a schematic illustration of filter 260, proximal fixedelement 264, and distal slider element 266 disposed about guidewire 262.Flexible coil 265 is attached to guidewire 262 proximal to fixed element264 or can be attached directly to fixed element 264 by welding,adhesives, or with assistance of a crimped band. In the embodimentshown, coil 265 is attached to guidewire 262 at attachment point 267.Flexible coil 265 is also attached (at attachment point 269) near toproximal end of guidewire 262 by welding, adhesives, with assistance ofa crimped band, or the like. Flexible coil 265 is a spring element. Thisincludes conventional spring coils as well as serpentine, substantiallyplanar coils, and flexible coil can be constructed of wire having round,flat, square, or other cross sectional shapes. Alternatively flexiblecoil 265 can be of braided construction or can be a tube from whichmaterial has been removed by way of etching, laser machining, grinding,electric discharge machining (EDM), and the like. Optional safety tether263 a is shown attached at proximal and distal locations of coil 265.More than one coil could be used in order to limit the axialextensibility of the flexible coil. Tether 263 a desirably runs axiallywithin the flexible coil 265.

FIG. 26B shows a lengthwise cross sectional view of the coil, whereintether 263 b is attached to the coil and to guidewire 262. In eitherarrangement, the tether is used to limit the coil's extension.

Spring coil 265 is positioned on the guidewire so that once the filterof the embodiment of FIG. 26A or 26B is positioned in the vasculature,spring coil 265 will be at least partially outside of the body. Thephysician will handle the spring coil during catheter exchanges over theguidewire 262/spring coil 265 assembly. Motion of the spring coil willbe absorbed by axial motion of adjacent coils so as to alter theirspacing without causing motion of the filter relative to the vessel.Filter 260 will exhibit some resistance against the vessel wall in orderto resist axial motion of guidewire 262 as transmitted through springcoil.

FIG. 27 is a schematic illustration of filter 270, proximal fixedelement 274, and distal slider element 276 disposed about guidewire 272.The guidewire ends distally at floppy tip 273. Proximally, the guidewireextends through elastomeric tubes 275 and 277 and hypotube 271, shown inpartial enlarged cross-sectional views. Elastomeric tubes are fused atone end to the end of hypotube 271 and at the other end to guidewire272. The elastomeric tubes allow hypotube 271 to move withouttransmitting excessive motion to wire 272, effectively minimizing motionof filter 270 during movement of hypotube 271.

Locks

FIGS. 28 to 36 illustrate various embodiments of distal protectionsystems that incorporate a locking means having a locked configurationand an unlocked configuration. In the locked configuration the positionof the functional element is fixed with respect to the guidewire beingmanipulated by the physician. This allows the physician to preciselymanipulate and control the position of the functional device duringdelivery and retrieval of the functional device. In the unlockedconfiguration the guidewire is moveable within a desired range withrespect to the functional element. This allows catheter exchanges andother treatment techniques performed during the intravascular procedurewhich can cause guidewire movement to be performed without dislodging ordisrupting the functional device.

FIG. 28A is a schematic illustration of a functional device whichincludes a filter 280, proximal fixed element 284, and distal sliderelement 286 disposed about guidewire 282. Proximal fixed element 284 isattached to tether 288 which is attached to a spring element 285 whichitself is attached within a hollow core 287a of a second (host)guidewire 287. Floppy tip 283 extends distally from filter 280. In use,spring element 285 manages tether 288 so that excess tether is withdrawninto hollow core 287a of second guidewire 287. In the aforementionedrespects the device of FIG. 28 is similar to the device of FIG. 19.Second guidewire 287 contains tabs 281 a that are slideably receivedinto longitudinal grooves 281 of proximal element 284. The groovesoppose each other, as shown in FIG. 28D. Proximal element 284 alsocontains circular groove 289 that can also slideably receive tabs 281 a.

FIGS. 28B, 28C, and 28D are cross-sectional views taken along lines B-B,C-C, and D-D in FIG. 28. Tether 288 and spring element 285 are notshown. FIG. 28B shows hollow core 287 a of guidewire 287. FIG. 28Cillustrates tabs 281 a that can be accepted in longitudinal grooves 281of proximal element 284. FIG. 28C illustrates opposing longitudinalgrooves 281 on proximal element 284. In this embodiment, two tabs areshown. In other embodiments, one or more tabs can be used.Alternatively, tabs can be located on fixed element 284 and cooperatinggrooves located on wire 287.

To deliver the filter, proximal element 284 is inserted into hollow core287 a, and tabs 281 a are slideably engaged into grooves 281. The tabsare advanced distally relative to proximal element 284 until the tabsreach circular groove 289, at which point guidewire 287 is rotatedrelative to proximal element 284 to cause the tabs to enter circulargroove 289. In this configuration wire 287 is locked to proximal element284 and filter 280. The filter can be precisely placed at a desiredlocation in the vasculature when the guidewire is locked in thisconfiguration.

Once the filter is placed, wire 287 is rotated relative to proximalelement 284 until the tabs align with longitudinal grooves 281. The wireis then withdrawn to disengage the tabs from the proximal element. Thewire may be further withdrawn to take full advantage of the tether andits ability to decouple wire motion from filter position. Because of theflexibility of the tether, wire bias is decoupled from the filter,leading to excellent radial independence of filter position relative towire motion. To recover the filter the reverse of the above steps isperformed in order to once again lock the wire into the proximalelement. Alternatively a catheter sheath can simply be advanced over thewire, tether, and filter, or the same can be withdrawn into a cathetersheath.

FIG. 29A is a schematic illustration of filter 290, distal sliderelement 296, and proximal slider element 294, and stop 291 disposedabout the wire 292. Proximally, wire 292 extends through hollow tube orsleeve 295 (shown in cross section as indicated by cross hatching) to alocking stop 297 which is moveable over wire 292 and is configured so itcan be locked in place on the guidewire at a desired location. Lockingstop 297 can be constructed of an elastomeric cylinder axially slitpartway through the cylinder diameter or in any of a number of ways asis apparent to those skilled in the art. To control the placement of thefilter in the vasculature, filter 290 is held against sleeve 295 bypulling wire 292 proximally relative to tube 295, until proximal elementabuts the distal end of tube 295, and then locking the tube in thisrelative position by sliding locking stop 297 distally relative to theguidewire until the stop abuts the proximal end of the tube. After thefilter is in place, locking stop 297, which is located outside of thepatient, is loosened by sliding proximally, allowing the filter to“float” while still tethered to the wire. Tube 295 may be withdrawnslightly to take full advantage of the range of motion allowed by thisdesign in its ability to decouple the tube motion from the filterposition. The length of tube 295 is sufficient such that during use theproximal end of tube 295 extends outside the patient and the distal endof tube 295 within the body, preferably extends to the treatment site.Thus, catheter exchanges can be made over tube 295 without disrupting ormoving filter 290.

An alternate embodiment of locking stop 297 is shown in FIGS. 29B and29C. FIG. 29B is a detail cross-sectional view of locking stop 297 whichcomprises friction stop 298 attached to sleeve 295. FIG. 29C is across-sectional view along line C-C of FIG. 29B. Friction lock 298contains slit 298 c which is adapted to compressively (and reversibly)receive wire 292. Space is provided distal to friction lock 298 to allowwire 292 to emerge from sleeve 295. A friction lock can be made of anyelastomeric material such as polyamide block copolymers (commerciallyavailable under the trade designation “PEBAX”), polyurethane, silicone,rubbers, and the like. Slit 298 c is preferably smaller in width thanthe diameter of wire 292.

In use, wire 292 is pulled proximally until the proximal element 294abuts against the distal end of sheath 295. Wire 292 is then pressedinto slit 298 c of lock 298. In this embodiment, coincidentally, stop291 will be in contact with and immediately distal to proximal element294, although this is not necessary in other designs with fixed proximalelements. With the wire locked into slit 298 c the device can beadvanced into the body and the filter placed with precision at apredetermined location. To release the filter, the wire is lifted out ofthe slit in the friction lock and preferably sleeve 295 is withdrawn ashort distance proximally to establish distance between the distal endof the sleeve and the proximal element.

FIGS. 30A and 30B illustrate a lock that can be fitted to devicessimilar to the device described in FIG. 11. Filter 300, proximal fixedelement 304, and distal slider element 306 are disposed about guidewire302, which extends proximally through hypotube 305. Hypotube 305 isshown in cross-section (as indicated by cross hatching), disposed aboutguidewire 302. FIG. 30B is a perspective view that shows in detail thathypotube 305 has two slits 303 disposed distally and are located in areduced diameter portion 301 of the hypotube. The reduced diameterportion of the hypotube is preferably formed by deforming the slitregion radially inwardly. The hypotube is biased radially inwardly aboutthe slits. It should be noted that more than one slit could be used, andthat the position of these slits may be varied. Wire 302 has a reduceddiameter portion 308 which is slideably received within the hypotubeincluding within the reduced diameter slit portion of the hypotube, andan intermediate diameter portion 307 which is slideably received withinthe hypotube but is frictionally engaged within region 301 of thehypotube. It is understood that the wire regions and tube slits can bearranged in other orders by one skilled in the art so as to achieve theobjects of this invention. It is further understood that the slits canbe axial, helical, or circumferential and may be of full or partialthickness. It is further understood that slits may not be necessary,simply rendering the tube non-circular in cross section may also achievethe desired goal. The frictional engagement of intermediate diameterportion within region 301 of the hypotube acts as a lock to the motionof the wire.

In use, the hypotube and wire are frictionally engaged by moving thehypotube distally until portion 307 is engaged in region 301 of thehypotube so as to lock the filter relative to the tube. The filter canthen be positioned within the body in a reliable and accurate manner.The tube and wire are then released from their frictional engagement byholding the proximal end of guidewire 302 while moving the hypotubeproximally to disengage portion 307 from region 301. Once released, thehypotube may be moved independently of guidewire 302 and filter 300 overportion 308 of the guidewire.

FIGS. 31A-31D are schematic illustrations of a distal protection deviceincluding a filter 310, proximal slider element 314, and distal sliderelement 316 disposed about guidewire 312. Distally, guidewire 312 endsat floppy tip 313. Optional stop 311 is affixed to guidewire 312 withinthe filter region, illustrated in the drawing at a midpoint of thisregion. Wire 312 and proximal slider element 314 are configured so thatguidewire 312 can be engaged with proximal slider 314 during deliveryand deployment of filter 310 and disengaged during performance of theprocedure to allow the guidewire 312 to move independently of thefilter. Shock absorber 315 comprises a sleeve of elastomer, braid,spring coil, or the like. Tabs 317 are attached to wire 312 within shockabsorber 315. Proximal slider element 314 is provided with lineargrooves 314 a as best seen in FIG. 31 C, which is a cross-sectional viewof the proximal slider taken along line C-C in FIG. 31A. FIG. 31D is anenlarged (side) cross-sectional view of slider element 314 shown in FIG.31A which shows annular internal recess 314 b, which slideably receivestabs 317. To controllably position the filter, tabs 317 are advancedthrough the linear grooves until they are within the annular internalrecess. Guidewire 312 is then rotated such that tabs 317 engage theannular internal recess. In this configuration there is positiveengagement between the proximal slider element 314 and the wire 312, andthe filter can be precisely placed in any desired anatomical location.After placement the guidewire 312 is rotated such that tabs 317 alignwith and engage the linear grooves and the guidewire 312 is retracteduntil the tabs 317 are free of the proximal slider element 314. In thisconfiguration the wire 312 is able to move without disturbing theposition of filter 310 and the shock absorber is positioned to providethe physician with a feeling of increased resistance if the guidewire ismoved distally to a position where the shock absorber approaches thefilter.

FIGS. 32 and 33 illustrate two embodiments of a coil wire clutch lockingmechanism.

FIG. 32 illustrates filter 320, proximal fixed element 324, and distalslider element 326 disposed about guidewire 322. The guidewire extendsproximally to coiled wire or spring 325 attached (at point 327) to anddisposed within hollow guidewire 329. Hollow guidewire may be hollowthroughout its length or may be hollow over only a portion of itslength. The hollow guidewire can be twisted during movement anddeployment of the filter to control the movement of the filter.

Specifically, the filter is locked into position by twisting the hollowwire in a direction that tends to enlarge the diameter of the coil.Friction of the filter against the vessel wall will tend to resist thisrotation, allowing the coil to lock within the hollow wire. Once lockedthe hollow wire and filter can be moved as a unit and the filter placedat an exact location within the body. To release the filter from thewire the wire is counter-rotated so as to decrease the coil diameter andthereby allow axial motion of the coil within the hollow wire.

FIG. 33 is a schematic illustration of filter 330, proximal fixedelement 334, and distal slider element 336 disposed about guidewire 332,which ends distally at floppy tip 333. The left side of the drawing isshown in a cross-sectional view, and the scale is exaggerated to showdetail. Proximally, guidewire 332 extends to and is attached withinhollow host guidewire 337, which is fitted with spring coil 335. One endof spring coil 335 attaches at attachment point 339 to interior ofhollow guidewire 337 and the opposite end of spring coil 335 attaches atattachment point 338 on the exterior of guidewire 332. Coil 338 isbiased to allow free axial translation of wire 332. In operation, wire332 can translate axially relative to hollow wire 337. To fix wire 332relative to hollow wire 337, hollow wire 337 is twisted in eitherdirection relative to wire 332 such that coil 335 tends to diametricallycompress, locking onto wire 332, or to diametrically expand, lockingwithin hollow wire 337. Frictional engagement of filter 330 relative tothe vessel will provide the needed counter rotational force for coilclutch actuation.

It is understood that it may be advantageous to make hollow wire 337hollow over its entire length and to extend wire 332 proximally suchthat it extends from proximal end of hollow wire. This configurationwill allow wire 332 to be held stationary while hollow wire 337 isrotated to engage the coil clutch. This embodiment eliminates the needfor filter 330 to resist rotational motion relative to the vessel.Advantageously rotational friction between wire 332 and hollow wire 337will hold the relative rotation between the two wires such that theassembly can be left in either a locked or an unlocked position.Friction between the wires can be augmented by any of a number of sealsas would be obvious to those skilled in the art. An advantage of thisdesign as compared to other lock designs is that the hollow wire neednot be advanced relative to the filter in order to lock the wirerelative to the filter, rather, a simple rotation of the pertinentelements will suffice, FIG. 34 has elements similar to that of theembodiment of FIG. 33. In this embodiment, a spiral cut tube 345 shownin cross-section is used to control wire motion. Similarly to FIG. 33,the left portion of this drawing is shown in a cross-sectional view, andthe scale is exaggerated to show detail. Filter 340, proximal fixedelement 344, and distal slider element 346 are disposed about guidewire342, which ends distally at floppy tip 343. Proximally, the guidewireextends through spiral cut tube 345. Guidewire 342 has splines 347 andtube 345 has one or more teeth 348 which are configured to slideablyengage the splines. Spiral cuts 349 preferably extend through the fullthickness of tube 345 except at proximal end 345 a where the uncut tubeserves as a handle and at distal end 345 b where the uncut tube servesto prevent diametrical enlargement of tube and thereby preservingslideable engagement of the teeth in the splines.

To fix the wire relative to the tube, the proximal end of the wire andthe tube are twisted relative to one another so as to cause the diameterof the spiral cut tube to shrink tightly about the wire. For example,the proximal end of the tube is twisted clockwise. The clockwiserotation of the tube's distal end is resisted since the teeth areengaged in the splines of the guidewire to prevent the distal end of thetube from rotating. To release the wire relative to the tube theseelements are counter-rotated so as to restore or increase the diameterof the spiral cut tube so that the wire is once again slideably receivedwithin the tube.

It will be understood by those skilled in the art that it isadvantageous to employ frictional locks similar to those discussed inconnection with FIG. 33 so as to maintain either the locked or unlockedposition, or both, of tube relative to wire.

FIG. 35 is a schematic illustration of filter 350, proximal fixedelement 354, and distal slider element 356 disposed about guidewire 352,which ends distally at floppy tip 353. Guidewire 352 is shown (dottedline) extending proximally through tube 355, which is shown in anexaggerated scale. Guidewire 352 is provided with a curvature or bendby, for example, heat setting, or simply by plastically deforming thewire. Once inserted in tube 355, guidewire 352 can be used incooperation with tube 355 to alternately lock the position of filter 350relative to tube 355 or to allow slideable decoupling of tube 355position relative to filter 350. In use, tube 355 can be slid over thebent wire to axially lock the two, and tube 355 can be oppositely slidrelative to wire 352 to unlock the two.

Alternatively the bend can be set or heat set into tube 355. In thisembodiment, collar 357 surrounds tube 355 and serves to straighten thetube so as to allow slideable motion between wire 352 and tube 355. Whencollar 357 is positioned away from the bent portion of tube 355 there isfrictional engagement of tube 355 relative to wire 352 and axial motionbetween the two is eliminated.

FIG. 36A is a schematic illustration of an embodiment with elementssimilar to that of FIG. 35, and again the left portion of the drawing isshown in exaggerated scale to illustrate detail. Filter 360, proximalfixed element 364, and distal slider element 366 are disposed aboutguidewire 362, which ends distally at floppy tip 363. In this caseguidewire 362 has an oval cross-section over at least a portion of itsproximal length and extends though tube 365. This is shown incross-sectional view in FIG. 36B taken along line B-B in FIG. 36A. Tube365 is rotationally affixed proximally to tubular lock 367. Tubular lock367 also has an interior lumen 367 a with an oval cross section thatslideably engages the oval portion of wire 362. Lock 367 is engaged byrotating lock 367 relative to wire 362 (as shown in FIG. 36C) such thata frictional engagement both prevents axial motion of the wire relativeto tube and rotational motion of lock relative to wire. The lock isdisengaged by counter-rotation of lock relative to wire.

A non-filtering occlusive embolic protection device can be built withlockable wire motion by simply incorporating a balloon instead of thefilter element and a hollow wire with valve instead of a solid wire indesigns similar to those described in connection with FIGS. 30, 33, 34,35, and 36.

Other Embodiments

One embodiment of this invention illustrated in FIG. 14A is an occlusivedevice comprising a balloon catheter. Other elements, as taught above,can be incorporated into this device, depending upon the desiredcharacteristics. A shock absorber on a balloon catheter can easily beconstructed by combining the shock absorber illustrated in FIG. 27 withthe balloon and valve teachings of FIG. 14. Similarly a balloonprotection device can be readily made based on the description in FIG.26 by substituting a balloon for the filter 260 and using a hollowguidewire 262 for inflation of the balloon. Similarly the device of FIG.19 can be adapted to balloon construction by using hollow versions ofthe wire 197, spring 195, and tether 198. The device of FIG. 22 can beadapted to a balloon device by adding a hollow coiled tube within thebraid 225 and by connecting the interior path of said coiled tube withthe interior of the balloon and the channel within a hollow wire 229.FIG. 24 and 25 can also be adapted to balloon protection devices byusing a hollow wire, adding a slideable seal to proximal slidingelement, and adding a communicating pathway between interior of hollowwire and interior of balloon. This pathway might include the intersticesof the braid, coil, or other shock absorber.

The protection device of this invention is particularly useful in theprevention of distal embolization of debris liberated duringinterventional procedures such as in cardiology, radiology, andneuroradiology procedures.

Although particular embodiments of the invention have been disclosedherein in detail, this has been done for the purposes of illustrationonly, and is not intended to be limiting with respect to the scope ofthe appended claims. It is contemplated that various substitutions,alterations, and modifications may be made to the embodiments of theinvention described herein without departing from the spirit and scopeof the invention as defined by the claims.

1. A method of filtering emboli from blood flowing through the lumen ofa vessel comprising: providing a distal protection device including aguidewire, the guidewire having first and second elongate members andhaving a locked configuration in which the first elongate member is notmoveable with respect to the second elongate member and an unlockedconfiguration in which the first elongate member is moveably connectedto the second elongate member, and a filter carried by the secondelongate member, the filter being expandable from a deliveryconfiguration to an expanded deployed configuration; locking the firstelongate member to the second elongate member so that their relativepositions are fixed; introducing the guidewire and filter in itsdelivery configuration into the lumen of the vessel; advancing theguidewire through the vessel until the filter is positioned at a desiredlocation distal to the treatment site; expanding the filter within thelumen of the vessel to its expanded deployed configuration; unlockingthe first elongate member from the second elongate member so that thefirst elongate member is moveable with respect to the second elongatemember over a range of motion from a first relative position to a secondrelative position without resulting in movement of the second elongatemember; and filtering emboli from blood flowing through the lumen of thevessel.
 2. The method of claim 1 further comprising advancing atreatment device over the guidewire to a treatment site after the firstelongate member has been unlocked from the second elongate member. 3.The method of claim 2 further comprising performing a percutaneousprocedure at the treatment site with the treatment device.
 4. The methodof claim 3 further comprising removing the treatment device.
 5. Themethod of claim 4 further comprising contracting the filter to aretrieval configuration and removing the guidewire and filter from thevessel.
 6. The method of claim 1 wherein the filter comprises a bodydefining a proximally facing opening when in the expanded deployedconfiguration.
 7. The method of claim 1 wherein the first elongatemember has a tubular body having a lumen with an interior diameter andthe second elongate member has a first region with an exterior diameterless than the interior diameter of the lumen of the tubular body, thefirst region being slideably received in the lumen of the tubular body.8. A method of occluding blood flow through the lumen of a vesselcomprising: providing a distal protection device including a guidewire,the guidewire having first and second elongate members and having alocked configuration in which the first elongate member is not moveablewith respect to the second elongate member and an unlocked configurationin which the first elongate member is moveably connected to the secondelongate member, and an occlusive device carried by the second elongatemember, the occlusive device being expandable from a deliveryconfiguration to an expanded deployed configuration; locking the firstelongate member to the second elongate member so that their relativepositions are fixed; introducing the guidewire and occlusive device inits delivery configuration into the lumen of the vessel; advancing theguidewire through the vessel until the occlusive device is positioned ata desired location distal to the treatment site; expanding the occlusivedevice to its expanded deployed configuration to occlude the lumen ofthe vessel; and unlocking the first elongate member from the secondelongate member so that the first elongate member is moveable withrespect to the second elongate member over a range of motion from afirst relative position to a second relative position without resultingin movement of the second elongate member.
 9. The method of claim 8further comprising advancing a treatment device over the guidewire to atreatment site after the first elongate member has been unlocked fromthe second elongate member.
 10. The method of claim 9 further comprisingperforming a percutaneous procedure at the treatment site with thetreatment device while the lumen of the vessel is occluded.
 11. Themethod of claim 10 further comprising removing the treatment device. 12.The method of claim 11 further comprising contracting the occlusivedevice to a retrieval configuration and removing the guidewire andocclusive device from the vessel.
 13. The method of claim 8 furthercomprising removing emboli from the blood in the occluded vessel at alocation proximal to the occlusive device.
 14. The method of claim 8wherein the first elongate member has a tubular body having a lumen withan interior diameter and the second elongate member has a first regionwith an exterior diameter less than the interior diameter of the lumenof the tubular body, the first region being slideably received in thelumen of the tubular body.
 15. The method of claim 8 wherein theocclusive device comprises an inflatable balloon.
 16. A method offiltering emboli from blood flowing through the lumen of a vesselcomprising: providing a distal protection device including a guidewire,the guidewire having first and second elongate members and having alocked configuration in which the first elongate member is not moveablewith respect to the second elongate member and an unlocked configurationin which the first elongate member is moveably connected to the secondelongate member, and a filter carried by the second elongate member, thefilter being expandable from a delivery configuration to an expandeddeployed configuration; locking the first elongate member to the secondelongate member so that their relative positions are fixed; introducingthe guidewire and filter in its delivery configuration into the lumen ofthe vessel; advancing the guidewire through the vessel until the filteris positioned at a desired location distal to the treatment site;expanding the filter within the lumen of the vessel to its expandeddeployed configuration; unlocking the first elongate member from thesecond elongate member so that the first elongate member is moveablewith respect to the second elongate member over a range of motion from afirst relative position to a second relative position without resultingin movement of the filter; and filtering emboli from blood flowingthrough the lumen of the vessel.
 17. The method of claim 16 furthercomprising advancing a treatment device over the guidewire to atreatment site after the first elongate member has been unlocked fromthe second elongate member.
 18. The method of claim 17 furthercomprising performing a percutaneous procedure at the treatment sitewith the treatment device.
 19. The method of claim 18 further comprisingremoving the treatment device.
 20. The method of claim 19 furthercomprising contracting the filter to a retrieval configuration andremoving the guidewire and filter from the vessel.
 21. The method ofclaim 16 wherein the filter comprises a body defining a proximallyfacing opening when in the expanded deployed configuration.
 22. Themethod of claim 16 wherein the first elongate member has a tubular bodyhaving a lumen with an interior diameter and the second elongate memberhas a first region with an exterior diameter less than the interiordiameter of the lumen of the tubular body, the first region beingslideably received in the lumen of the tubular body.
 23. A method ofoccluding blood flow through the lumen of a vessel comprising: providinga distal protection device including a guidewire, the guidewire havingfirst and second elongate members and having a locked configuration inwhich the first elongate member is not moveable with respect to thesecond elongate member and an unlocked configuration in which the firstelongate member is moveably connected to the second elongate member, andan occlusive device carried by the second elongate member, the occlusivedevice being expandable from a delivery configuration to an expandeddeployed configuration; locking the first elongate member to the secondelongate member so that their relative positions are fixed; introducingthe guidewire and occlusive device in its delivery configuration intothe lumen of the vessel; advancing the guidewire through the vesseluntil the occlusive device is positioned at a desired location distal tothe treatment site; expanding the occlusive device to its expandeddeployed configuration to occlude the lumen of the vessel; and unlockingthe first elongate member from the second elongate member so that thefirst elongate member is moveable with respect to the second elongatemember over a range of motion from a first relative position to a secondrelative position without resulting in movement of the occlusive device.24. The method of claim 23 further comprising advancing a treatmentdevice over the guidewire to a treatment site after the first elongatemember has been unlocked from the second elongate member.
 25. The methodof claim 24 further comprising performing a percutaneous procedure atthe treatment site with the treatment device while the lumen of thevessel is occluded.
 26. The method of claim 25 further comprisingremoving the treatment device.
 27. The method of claim 26 furthercomprising contracting the occlusive device to a retrieval configurationand removing the guidewire and occlusive device from the vessel.
 28. Themethod of claim 23 further comprising removing emboli from the blood inthe occluded vessel at a location proximal to the occlusive device. 29.The method of claim 23 wherein the first elongate member has a tubularbody having a lumen with an interior diameter and the second elongatemember has a first region with an exterior diameter less than theinterior diameter of the lumen of the tubular body, the first regionbeing slideably received in the lumen of the tubular body.
 30. Themethod of claim 23 wherein the occlusive device comprises an inflatableballoon.